FaceTime Video / Audio still runs on iOS and I believe the Audio version also runs on OS X Mavericks. I'm trying out Google Hangouts on iOS since I have a Google Voice number. So, I think when 4.4 comes out, it's gonna be worthwhile for you and your buddies who'll take advantage of Google+.

although there are many apps that do what facetime does, you will NEVER find one as good. Even though apple was a late to the game with facetime, it is DRASTICALLY a better experience. Cleaner, clearer and crisper in ever way for both audio and video. I have used dozens of different phones from nexuses' to Notes 2's, s3', iphone 4, 5 etc and also tried the various apps like hangouts, skype, facetime, etc. in each and every case FACETIME was easily the best by far.